Among all outdoor activities cycling is one of the most popular, especially road and mountain biking. For many, mountain biking is the most fun because mountain paths, desert trails, and country roads offer resplendent views of nature, fresh air, and respite from vehicular traffic. Structurally mountain bikes are considerably rugged and built to withstand hard, intense use over rugged terrain. Because mountain paths and nature trails are often quite hilly, mountain bikes are furnished with drive trains that offer a wide range of gearing ratios from very low gearing for climbing and high gearing for flat terrain.
Of great concern now is the preservation of natural resources, such as water and especially fuel oils. Although sport-utility vehicles and trucks and other large passenger vehicles were once popular and in high demand, they consume large amounts of fuel as a result are becoming increasingly less popular. Because people are becoming increasingly energy conscious, efforts to find convenient and energy-efficient transportation are now on the rise. Although motorcycles, small passenger vehicles, hybrid vehicles, and electric vehicles offer excellent energy-efficient modes of transportation, the technology and efficiency of bicycles and especially mountain bikes has remained ignored in terms of providing a baseline structure for a motorized vehicle.